According to the Chinese Medical Journal study, "there have not been any studies arranging AS in groups according to vitamin D levels and determining any differences among these patients in terms of disease activity, functional status, quality of life, and other clinical parameters." Thus, this study is one of the first of its kind.

The study's results state that even blood tests for inflammation including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were higher in those with ankylosing spondylitis and deficient levels of vitamin D.

Read the review's abstract as well as the full text version on the affects of Vitamin D and AS.

About the writer: Chris Miller is the Director of Programs at the Spondylitis Association of America and is Managing Editor of SAA's news magazine, Spondylitis Plus. He has been at SAA for nine years.